Gas calorimeter



Oct. 21, 1930. H HER 1,779,373

GAS CALORIMETER Filed March 9, 1928 IIIIIIIIIIIIIIIIIIIIA 55 84 70 86 awuemtoz (JHMES 1D. F/SHER 851 his Qua/nu;

Patented Oct. 2 1;. 1930 UNITED STATES PATENT OFFICE JAMES P. FISHER, OF BARTLESVILLE, OKLAHOMA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO BURGESS-PARK COMPANY, O

DELAWAPE F MOLINE, ILLINOIS, 'A CORPORATION OF GAS CALORIME'IER.

The present invention relates to gas calorimeters and more particularly to those adapted to determine the heat value of gas from a gas source in a non-intermittent manner. v

, It has been proposed to measure and record the calorific value of gas from a gas source in a non-intermittentmanner. This method of determining the calorific value however involves pumping proportional quantities of gas and water for considerable periods of time and difficulties have been encountered in obtaining satisfactory mechanism for this purpose; It is moot the objects of the present invention to provide simple and reliable mechanism for pumping predetermined proportions of gas and water.

Further objects and advanta es of the present invention will be clear to t ose skilled in the art from the following description taken in connection with the accompanying drawings, in which: i v Fig. 1 is an elevation of a calorimeter apparatus including mechanism according .to the present invention;

Fig. 2 is a detail elevation of a portion of the apparatus illustrated inFig. 1;

Fig. 3 is a section taken on the line 3 3 of Fig. 2 looking in the direction of the arrows;

Fig. 4 is a partial side, elevation of a portion of-the apparatus shown in Figs. 2 and 3; Fig. 5 is an elevation of another portion of the apparatus illustrated in'Fig. 1;

Fig. 6 is a section on a line6-6 of Fig. 5 looking in the direction of the arrows;

Fig. 7 is an elevation view in detail of the pumping mechanism shown in Fig. 1, parts being broken away and parts being shown in section for purposes of illustration. In the apparatus illustrated in the draw.- ing, gas whose heating value isftobe determined is introduced into the apparatus through the valve 10 in pipe 12. It is common practice to determine the heating value of gas bymeasuring the temperature rise of a given amount of water produced by burning a given quantit of gas under standard conditions of tem ratureyand pressure. Water for use in determining the calorific value of the gas may be introduced into the apparatus through the valve 14 in the pipe 16. It has been proposed to compensate the apparatus for varying changes in pressure and temperature of a gas, but I prefer to maintain the density of the gas constant, and for this purpose a varying amount is wasted from the pipe 12 to maintain a constant density at the point the gas is metered to the burner. The mechanism for-this purpose includes 9. Waste pipe 18 connected to the pipe 12, pipe 18 having a Waste controlling and pressure controlling mechanism 20 connected therein. The specific embodiment of pressure controlling mechanism 20.illustrated in the drawing includes a section of rubber tubing 22 connected into the pipe 18, means being provided in connection with tubing 22 whereby it acts as a pinch valve. For this purpose, the mid-portion of tubing 22 has its edges clamped by a cut-away clamp block 24 and a bar 26 (as 70 illustrated in Fig. 4) so that the natural resiliency of the tubing 22 exposed by the cut-away portion of the clamp block 24 is free to expand to'a certain amount thereby providing a restricted Waste passage '28 for the escape of gas. In the arrangement illustrated, the size of passage 28 is restricted automatically to the desired degree to maintain the desired density in pipe 12. The means for restricting the passage 28 includes a spindle 30 entering the cut away part of block 24. One end of spindle 30 is in contact with the surface of the tube 22 in the center of block 24, and the longitudinal position of spindle 30 is determined by a diaphragm 34. Diaphragm 34 is subject on one side to the pressure of gas in pipe 18 and on the other side to a pressure varying with, the temperature of the Water delivered by pipe 16 to maintain the density constant at a point in the apparatus at which the gas and Water are at the same temperature. The diaphragm 34 ismounted in a casing 36, the edges of the diaphragm being clamped between two-portions of the casing. On one side of diaphragm-34 is a chamber 38 connected to the 'pipeql8 thr'oughthe nipple 40 on the inlet sideofthe passage 28. On the other side of the diaphragm .34 is a closed chamber 42, formed by. diaphragm 34 and a metal cup 44, and containing a fixed weight 34. The slight resiliency of the tubing 22 ing through pipe 19 where it presses against spindle 30 is preferably taken up by adjusting the position of the diaphragm. A small flexible diaphragm 46 surrounding spindle 30 forms an opening in the casing permitting the spindle to pass through it so that the movement of the diaphragm 34 may be transmitted outside of casing 36 without leakage of gas. For any constant temperature, the gas in this chamber will exert a constant pressure against the diaphragm 34. The opposite face of diaphragm 34 being subject to gas pressure from pipe 18, the position of the diaphragm will vary with variations in pressure of the gas. It will be seen that as the pressure of gas in pipes 12 and 18 increases, the pressure against diaphragm 34 in chamber 38 also increases thereby moving the diaphragm 34 in the direction to permit the passage 28 to enlarge and thereby increase "the escape of gas from the pipe 12. Increasing the escape of gas evidently reduces the pressure in the pipe 12. On the other hand, if the pressure in pipe 18 decreases,

pressure in chamber 38 also decreases thereby causing spindle 30 to restrict the passage 28 and to thereby build up pressure in pipes 18 and 12. It will be seen therefore that the valve mechanism 20 together with its manner of connection to pipe 12 is such as to maintain a constant pressure in the pipe, so'long as the temperature of the gas in chamber 42 is constant. If the temperature in chamber 42 varies, the pressure in pipe 12 will be auto-. matically varied by an amount proportional to the change in absolute temperature where- 'by the gas will be at constant density when brought to the temperature of the gas in chamber 42, which is the same as the water temperature. It'is preferred that gas escap- 4$ The escaped gas is thereby prevented from becoming a nuisance, and moreover the quantity of gas being wasted is made evident to the operator, who can therefore regulate the valve 10 to maintain a low, rate of gas wastage.

The temperature of the as in chamber 42 is maintained, the same ast e temperature of the gas being metered in meter 52 by ,the stream of water fed to the calorimeter through pipe 16. Part of this water is wasted and part of it passes through the meter 52 to the calorimeter. It is desirable to maintain a temperature of this water near that of the room so there will be no substantial change in temperature between chamber 42 and e burned as' indicatedat meter 52. A heater diagrammatically indicated at 50 and which can be automatically controlled can be provided to maintain the Howtus, it is necessary to supply the calorimeter proper with water and gas in constant proportions. In the embodiment of the invention illustrated in the drawing, the gas and water for the calorimeter proper are measured and pumped by a pumping mechanism indicated in general'by reference character 52. Pumping andmeasuring mechanism 52 is illustrated in detail in Fig. 7 and includes inlet chamber 54.' The gas from pip'e 12 is conducted to chamber 54 through a pipe 56, pipe 56 entering chamber 54 at the top. Water pipe 16 also enters chamber 54 as appears in Fig. 7. The pumping mechanism withdraws gas and water from chamber 54 and the proportion of water volume to gas volume so withdrawn depends upon the water level in the chamber 54. It is v water level in chamber 54 at a predetermined I adjustable level. For thispurpose a vertical upper edge 62 of the pipe 58 determines the desired therefore to maintain the water level in. chamber 54 and the position of.

the edge 62 can be adjusted by sliding the pipe 58 in the stufling box 60. Water overflowing through the pipe'58 maybe run to waste as indicated at 64. The pi e 58 contains a trap 65 to prevent escape 0 gas at 64. Moreover, the discharge point at 64 is preferably visible so that the amount of water running to. waste can be regulated.

The pumping mechanism 52 preferably'includes a pumpmg element of the screw type comprising an outer barrel or shell 66 within which is a screw comprising a shaft 68 having one or more threads 70 thereon extending from shaft 68 to the inner surface of the bar rotation of the barrel 66 causes the threads therein to withdraw water and gas from the chamber 54 and to discharge it into a similar chamber 76'at the other end of the screw. It will be. noted that mechanism 52 cannot abstract gas from chamber 54 unless the water level in the mechanism is at least as high as the lower edge of shaft 68. The diameter of shaft 68 therefore determines the permissible amount of variation of the water level in the mechanism 52 and therefore determines the possible variation in the ratio of water and air pumped by the mechanism in a given amount of time. It is preferred therefore that the diameter of shaft 68 be at least twice the height of the thread or threads 70 as is the case in the device illustrated in the drawing. The chambers 54 and 76 have beveled faces complementary to the journals 74 and acting as bearings therefor. The chambers 54 and 76 together with barrel 66 may conveniently be mounted by pins 7 8, 78 in a frame 80 in which is carried a motor 82 having a worm drive including a gear 84 fixed on the barrel 66 for-revolving the barrel when the motor is running. 0

Water and gas are withdrawn from cham-' ber 76 and conducted therefrom to the calorimeter proper. Water is taken fromchamber 76 through the vertical outlet pipe 86 which enters the bottom of the chamber 76 through the stuffing box 88. The horizontal upper edge 90 ofpipe 86 should be at sub stantially the same level as the upper edge 62 of pipe 58 so that the water-level in cham-- bers 54 and 76 will be substantially the same. For this purpose, outlet pipe 86 is made adjustable in stuffin box 88. Gas is withdrawn from the chamber 76 through the pipe 92 entering-chamber 76 through thetop. It is essential that the pressure of the gas in pipe 92 and in chamber 76 should be substantially the same as that in pipes 12 and 56 and chamher 54. In order to maintain the equality of pressure mentioned, a regulating valve 94 is connected into pipe 92. Valve 94 is of a type somewhat similar to the valve mechanism 20 previously described. Valve 94 as illustrated includesa rubber tubing 96 forming a pinch valve of the type previously described in connection with mechanism 20. Valve mechanism 94 includes also a casing 98 within which is mounted a diaphragm 100. The edges of the diaphragm 100 are clamped by the edges of the casing 98, the diaphragm thereby dividing the interior of the casing into two chambers. On cine side of the diaphragm 100, casing 98 is connected to the pipe 92 through a nipple 102. The chamber in casing 98.0n the other side of diaphragm 100 is connected through pipe 104 to the pipe 12. A pin'or spindle'106 moreover transmits movements of the diaphragm 100 to the constricted portion of thetubing 96 so as to regulate the amount of gas flowing therethrough. It will be evident from the previous description of the valve mechanism 20.

that the valve'94 will operate to maintain the pressure in the pipe 92 substantially equal to that in pipe-12. It will be noted that the pressure connection 102 to the side of the diaphragm 100 connected to pipe 92 is similar to the arrangementpf valve mechanism 20, on the inlet or upstream side of the valve.

The pipes 86 and 93 conduct the gas and water to the calorimeter proper indicated at 108. The calorimeter 108 illustrated in the drawing is assumed to be of the well-known Junkers type and thereforene'eds no further description. The calorimeter, however, may I be of any convenient type within the present invention. In the arrangement illustrated the gas is burned at 110. The calorimeter is illustrated as having mercury thermometers 112, 112 and also a continuous resistance differential thermometer 114 located in the water of the calorimeter at the sides thereof. The electrical temperature differential recording mechanism is diagrammatically illustrat'edas 116. The function of the calorimeter. proper and the temperature indicating and recording mechanism may be the same as for any calorimeter of this type and need not be described.

The functioning of each feature of the instruments ordinarily available. At any time, the gas passing to the calorimeter burner can be diverted through a standard measuring device such asa standard meter or cu. ft. bottle and the amount of water passing through the calorimeter for the same period of time can be caught and measured or weighed. The gas volume as measured can be reduced to'standard barometerand a U-tube to the pipes 56 and 92. The temperature recording apparatus 114 can .be checked by the mercury thermometers. It will be obvious that the correct functioning of the apparatus herein disclosed is dependent upon the capacity of the valve mechanism'20 to properly control the pressure in the pipe 12. A given mechanism 20 can maintain the constant density of the gas calorimeter can be calibrated at any time by or meter 52 can be checked by connecting at the outlet of meter 52 only within certain variations in the effective pressure of the gas supply, and variations in temperature of the water supply. Regulating valve mechanism 20 can operate only to reduce the pressure in 'pipe 12 and it is evident that the pressure in pipe 12 a little above atmospheric pressure at any temperature of water that will be encountered. Obviously this requirement will be different at different altitudes. It is not probable, however, that a given instrument will be required to operate at various alti tudes or in various general climatic conditions, but if an instrument is designed for one climate and then moved to quite I dilferent one, it may be necessary to cool or heat the water passing to chamber 48 of valve mechanism 20, although, in general, the heater 50, if used, is not essential. For a location andclimate similar to that of-Bartlesville, Oklahoma, it is considered satisfactory to make .the weight of the gas in chamber 42 such as to give a pressure of thirty inches of mercury at 60 F., since the barometer in Bartlesville is always less than thirty and it is notprobable that the room temperature or water temperature of the instrument would fall below sixty degrees F.

In designing an apparatus for a colder climate, it might be well to increase the density of the gas in chamber 42 somewhat, say to 110% of the 30-60 condition. The chamber 42 having been sealed, the absolute pressure in the chamber varies as the absolute tem perature. Assuming that the chamber 42 has been filled with gas and sealed under conditions of thirty inches of mercury pressure and degrees F. temperature, if the coolilig'water should reach a temperature of the pressure in chamber 42 would be 32.3" and the-pressure in pipe 12 could not fall below this. -The apparatus might not factorily at this temperature.

function properly under this condition and t might be necessaryto cool the water entermg t rough pipe 16. However, a tap water temperature of 100 F. probably will never be encountered in Bartlesville, Oklahoma. A

tap water temperature of 90 F. is not improbable, but there is no reason to'suppose that the apparatus would not perform satishe foregoing discussion assumes that the gas su ply to pipe 12 is restricted sufliciently so that the valve mechanism 20 can' always reduce the pressure in pi 12 to the required degreeto maintain nstant density at the outlet of the meter- 52, or at least so that the pressure in pipe 12 shall be as low as that in chamber 42.

, well regulated.

,about 15 degrees Fahrenheit.

In putting the apparatus, according to the present inver tion, into operation, it is necessary to adjust gas cock 10 and Water cock 14 to furnish a slight excess of both gas and water to the instrument more than will be handled by the gas and water measuring pump 52. Pump 52 in conjunction with automatic valves 20 and 94 will extract both gas I and water from chamber 54 at constant rates.

The surplus water will overflow and be visible at 64 and the surplus gas will be released by valve 20 and if ignited at 49, will be visible lower than that required to bring the density to standard at the temperature of the water in 48 and 52. In this case the pressure on the gas supply must be increased or the temperature of the water supply reduced until the valve 20 again will, release a surplus of gas at 49. When a small flame is burning at 49'and a small stream of water wasting at 64,

with meter 52 operating, the gas and water supplies to the instrument are sufliciently In building an apparatus according to the present invention, it is considered satisfactory to make tubes 22 and 26 of ordinary soft rubber laboratory tubing of about inch diameter and 1 inch bore. The water and gas overflow pipes should be selected of suificient size that no back pressure shall be placed on, gas escape passage 28 and that there shall be sufficient weir surface at point 62. Pipe 86 should, of course, be the same size as pipe 58. The remaining pipes can be made satisfactorily and conveniently of inch outside diameter copper or brass tubing or with A; inch or 1; inch iron or brass pipe.

In ordinary practice with' natural gas, the Junkers calorimeter burns about of a cubic foot of gas per minute and the water is adjusted to secure a temperature rise of This temperature rise requires about seven pounds of water per minute. One tenth of a cubic foot of water weighs 6.25 pounds. It is evident therefore that pipes 58 and 86 should be set so that meter 52 will deliver substantially equal volumes of gas and water when the present appkarat'us is operating on natural gas. In ot er words, the tops ofpipes 58 and 86 shouldbe set approximately at the level of the axis of rotation of barrel 66. When obtaining the calorific value of manufactured gas, the volume of gas space in meter 52 should be relatively larger and Diaphragms 34 and 100 preferably are rather deeply corrugated and made. from very thin metal preferably copper and they should be adjusted to operate near their normal or flat position. This adjustment can be made by selecting pins 30 and 106 of proper length and by selecting the proper amount of gas to be held in chamber 42.

It will be seen from the foregoing that, according to the present invention, provision has been made for continuous automatic operation in which gas and water will be measured accurately into a Junkers or other 4 type calorimeter. The )IOPOItlOIL. between the volume of gas and the volume of water can be set at will witlpin certain limits. and when nce set will remain constant. Since the de ity of the'gas is maintained constant the ratio between the amount of gas and water will remain constant. This ratio can be made Ivolume of gas to 1 volume of water or two volumes of gas to 1 of Water, or any other desirable ratio; I

The gas will be measured at an automatically controlled pressure a little above at mospheric pressure, this pressure variation being maintained automatically so that-the same weight of gas will be put through the metering element 52 per revolution regardless of changes in barometric pressure and atmospheric temperature). This pressure can be arranged to correspond to any desired standard of measurement as 30 inches of mercury (and 60 F.), or preferably some fixed number of times the standard, as for instance,y110% of 30 inches, (60 F. conditions). Moreover, as the mass of gas is small in-comparison to the mass of water pasging through the meter 52 and as the gas is n contact with the Water and with the threads and shaft 68 which pass alternately through the water and the gas, the gas is measured at the temperature of the water going through the meter and at a pressure automatically controlled by valve 20 to correspond with that temperature to give a constant density of the gas being measured. This insures a constant ratio be tween the amount of gas and amountof water pumped by the meter 52 to the calorimeter.

Means is also provided whereby the pressure is balanced across the metering device so that the meter 52 will at all times operate agalnst zero pressure differential and its volumetric capacity is therefore fixed and reliable After the gas has beenmeasured it passes through a regulator before going to the calorimeter burner, so that the variations in size inthe orifice in the. burnerwvill/have no effect on the measurement of the gas. The calorimeter element proper can be an ordinary Junkers type calorimeter with the usual mercury observation thermometers. In addition to these mercury thermometers a differential recording thermometer 116 or any other type of instrument for'measuring the difference in temperature can be applied and this difference of temperature will be directly proportional to the heating value of the'gas passing through the instrument and can be recorded directly as heating value of the gas. As above noted, the gas passing from the metering element is maintained at I constant density. As it is metered in contact with the water passing to the calorimeter proper, its humidity is also maintained con-.

stant if the water temperature is constant and there need be no correction device Whatever applied to the temperature recording or indicating instrument, and the simplest and cheapest reliable type of recording or 5 indicating instrument available may be used.

It will be noted that the design of the-gas andwater'metering element involves a. very small volume of gas trapped in the metering device. The special design metering device to keep this volume small is one main feature ofthe present calorimeter, as a small volume of gas passing through the calorimeter reduces the time lag between a change in the calorific value of the gas and its indication. All gas passages from the intersection of pipes 12 and 18 through tothe burner at 10 are preferably kept at a. minimum length and cross-section to assist in'minimizing the time lag of the instrument. There is, therefore, according'to the present invention, a minimum lag between a given change in the calorific value of the gas and the recording or indication of said change by the present apparatus.

The apparatus according to the present invention therefore that the volume of gas in the metering mechanism plus that in the connections between the metering mechanism and the burner of the calorimeter is much less than in the ordinary continuous calorimeter.

Having thus describedmy mvention, I claim:

1. The combination in a calorimeter ap paratus, of a pump metering gas and water in fixed proportions by volume, a combined gasv and water chamber at the intake side of said pump, a pressure regulator acting on the gas flowing to said chamber, a combined gas and water chamber on the outlet side of said pump, and a pressure regulating valve acting onthe gas flowing from said second chamber.

2. The combination as stated in claim 1 and in which the pressure regulating valve acting on the gas flowing from the pump outlet maintains a pressure on the pump outlet equal to the pressure at the pump inlet.

3. The combination as stated in claim 1 in v which the pressure regulating valve acting on the gas flowing from the pump outlet maintains a pressure on the pump out et equal to the pressure at' the pump inlet and in which the ressure regulatmg valve a'ctin on the gas owing from the second chamber mcludes an operating diaphragm one side of WhlCh 1s subject to pressure from the chamber on the intake side of the ump.

4. The combination as stated in claim in which the pressure regulating valve acting on the gas flowing from the pump outlet maintains a pressure on the pump outlet equal to the pressure at the pump inlet, in which the pressure regulating valve acting on the gas flowing from the second chamber includes an operating diaphragm one side of which is subject to pressure from the chamber on the intake side of the pump, and in which the dia hragm of the pressure regulating valve acting on the gas flowing from the pump outlet is subject on its other side to the pressure of gas on the inlet side of the valve of which it is a part. p

5. The combination in a calorimeter aparatus, of two combined gas and water chambers'and a pump intermediate said chambers and metering gas and water from one to the other, said pum including a screw thread and a shaft on w ich said thread is mounted, said shaft having a diameter relatively large as com ared to the height of the screw thread.

6. T e combination in a calorimeter apparatus, of two combined water and. gas chambers and a pump intermediate said chambers and metering gas from one to the regulating to said pump to automatically vary the presother, said pump having a barrel mounted for rotation, a screw thread within said barrel and in contact with the inner face thereof, and a shaft contacting with and surrounded by said thread.

7. The combination as stated in claim 6 and in which said barrel is journalled on said chambers.

8. The combination in a calorimeter apparatus of a pump metering gas and water 1n fixed proportions by volume and a pressure valve,acting on the gas flowing sure in the pump to maintain the density of the gas constant on the pump outlet.

9. The vcombination 1n a calorimeter apparatus of a pump metering gas and water in fixed proportions by volume and a pressure regulating valve acting on the gas flowing through said pump, the said pressure re ulating valve comprising a closed cham er containing gas, sald chamber having a heat transferring wall, and an operating diaand connections for flowing phragm forming one side of said chamber;

water passing to the pum in contact with said heat trans ring wa In testimony whereof I aifix my signature.

JAMES P. FISHER. 

